Carburetor



Aug; 19; 1924. f 1,505,921

F. F. FLINT y CARBURETOR Filed oct. 29, 1923 :s sh'eets-sheet 1 Aug. 19 ,1924. AHL1,505,921

F. F. FLlNTv CARBURETOR Filed Oci. 29, 1923 5 'Sheets-Sheet 5 Patented Aug. 19, 1924.

UNITED STATES PATENT :oI4"1=lcE,.Yi

FLOYD F. FLINT, OF DETROIT, MICHIGA. ASSIGNOR OF ONE-HALF T0 MAXWELL:

BENJAMIN, 0F DETROIT, MICHIGAN. z

CARBURETOR.

Application filed October 29, 1923.

To @ZZ lwhom t may concern:

Be it known that FLOYD F. FLINT, citizen of the United States, residing at Detroit, in the county of l/Vayne and State of Michigan, has invented certain new and useful Improvements in Carburetors, of which the following is a specification.

This invention relates to carburetors such as are used in connection with automobiles and other internal combustion engines.

yMore particularly the invention relates to means for supplying liquid fuel to a carburetor.

Heretofore it has been common to provide a fuel supply to carburetors from a tank lower than the instrument by suction produced in a chamber interpos-ing between the carburetor proper and the fuel supply tank. It has also been the common practice to utilize the suction of the engine for the purpose of producing a partial vacuum in the intermediate chamber. and thus raise the fuel from the fuel tank by atmospheric pressure.

This method of operation, while quite well known, is open to serious objections. In the ilirst place there is necessarily required an extra tank or chamber and the connections thereof are quite complicated in their nature.

One important object of the present invention is to provide an improved form of fuel feed for carburetors wherein the use of an auxiliary or intermediate chamber may, if desired, be entirely disposed with.

A second important object of the invention is to provide an improved fuel feed of this class wherein the connection between the supply tank and carburetor may be a simple pipe line with the valves or other parts between thc tank and the carburetor thus eliminating the con'iplicated pipe system necessary with the usual vacuum tank.

In the ordinary vacuum tank feed other objections exist by reason of the fact that it is not possible when using the vacuum effect produced by the engine operation, to control in a proper manner the suction for lifting the fuel, since changes in the operating condition of the engine cause such suction to vary rwithin extremely wide limits.

A third important object of the invention is to provide an improved arrangement of Serial No. 671,504. I i

fuel feed which will be independent of the suction produced by the engine operation.

A still further objection that exists in the present system is that such system is applied directly to a 'carburetor and it is necessary to have the' suction pipe from the fuel receiving chamber closed of'I1 at intervals from the source of suction in order to permit flow of the fuel from the chamber to the jet noz'- i Zle. lhen this is done under the present arrangement it will happen that the valve will not open at the proper time and consequently as' soon as the fuel has been eX- hausted from the receiving chamber the en'- i' gine will stop.

A fourth object of the invention is to provide an improved fuel feed having` a relief valve means whereby the valve control in v,

the connection between the fuel receiving tank and the carburetor will be properly operated at all times and under all conditions of engine operation. i

A fifth' important object of the invention In the accompanying drawing/s like characters of reference indicate like several views, and:

Figure 1 is a side elevational view partly in section of a carburetor especially adapted for use in connection with this invention.

Figure 2 is a plan view thereof.v lFigure 3 is a horizontal section'tliereof and a special form of thepump used 'here with. n l 'i Figure lis a side elevation of such pump. Figure 5 is a section on the line '5 5 of Figure 3. i i

Figure 6 is a Figure 3.

parts the section on the line' 6 6 of Figure 7 is a'diagrammatical viewishow- A merely to show one of such forms, the invention not being confined to the particular form and proportions herein illustrated.

v In this'embodiment there is provided a hollow bottom 10 constituting a reservoir. This bottom is of elongated form and at one end thereof 'there is superimposed on the bottom a `fioat chamber 11.` This float chainber 11 consists of a cylindrical tube 12 forining the side wall thereof, this tube being seated on a gasket 13 and having a top 14. closing the upper end. The tube is held on the gasket and the top of the tube by means of suitable studs 15, which extend tlii'ough the top `and intothe top of the reservoir 10. The top of the reservoir 10 is provided, centrally of the tube 12, with an opening 1G whereinis seated a housing` 17 having a valve ca`sing18 projecting from one side. In this valve casing is fitted a poppet valve 19 which opens from the chamber 11 inwardly to the reservoir 10 at certain times during the operationand closes communication between the ioat chamber and reservoir at other times. Located centrally of the housing 17 and. depending from the top thereof is a valve stem guide 20, the lower end of the vertically movablev valve stem 21 having fixed thereon a lower collar 22, and anupper collar 23 in s aced relation. Above the upper collar 23, tie valve stem carries a valve 24 which serves to close the lower end yof a suctionpipe 25 screwed through the top` 14. Screwed into one side of the top is apilpe T 26 having its upper end closed norma ly by a plug 27. To this pipe T is connected a casting 28 containing a downwardly openingrelief valve 29 of ordinary and well known construction. Intermediate the ends of the T a branch pipe or conduit l3() leads to a pump indicated in general at P. Similarly ythere is provided for the gasket a supply conduit 31 which may lead directly to the supply tank T as shown in Figure 7 or to an intermediate vacuum chamber 32 iii which case the pipe 30, instead of being connected to the top of the fioat chamber as just described, will be connected with its'relief valve 29, to the top of the vacuum chamber B2.` However, it is preferred to use the'form shown in Figure 7 since with this form the invention is adapted for employment with any of the well known forms of carburetor full line position, shown inithat figure.

without any changes whatever in the jet nozzle and venturi arrangen'ients.

At`33 is the float and opening into the housing17 is a. vent tube 34 which passes downward through the float, as shown in Figui'e 1,and is provided at its upper end with a slight clearance, as shown at By this arrangement a proper admission and exhaust of air is permitted in the lower and upper chambers.

The carbureting portion of the device is indicated in general at C and since the specific construction of this part of the device forms no portion of the present invention it will not be described in detail.

TVith respect to the pump P, I have found that neither the ordinary type of reciprocating pump nor a rotary pump will serve to effect proper vacuum conditions in the ap aratus. There has accordingly been provi( ed a special form of oscillating pump, which has the advantage of producing in a prescribed manner the desired vacuum conditions and which also is inherentlyso constructed as to be iioiseless in operation and self-lubricating. To this end there is mounted on a suitable support, which may be a part of the engine, a bracket 36 having a leg 37, which is preferably arrangedpin a vertical position. Through this leg 3i' extends an opening 38 and joui-nailed in this opening is a pivot shaft 39 sui'iporting an oscillating cylinder 40. The shaft projects laterally from the central part of the cylinder and the cylinder is provided with a flat side 41 bearing against the inner side of the leg 37 or plate 36. Surrounding the shaft 39 is a spring 42 which bears at one end against the leg 37 and at its other end against a washer 43 held on the shaft by `a nut 44. `By this means the cylinder is held :firmly pressed against. the plate 41 but may yield sufficiently to permit lubrication of the l Contact surface. In the plate 37 is provided an exhaust port 45 and inlet port 4t`ito which the conduit 30 is connected. Cooperating with these ports is a port 47 which leads from the Aflat side of the cylinder to its interior and is so positioned that oscillation of the cylinder causes the port 47 to register alternately with the ports 45 and 46. Mounted reciprocally in thecylinder is a piston 48 which moves between the dotted ine position, shown in Figure 3, and the It will thus be observed that the piston moves between a point adjacent the port 47 and a point considerably spaced from the open end of the cylinder so that a luliricating chamber 49 is formed at this end. From this lubricating chamber' leads a lubrication port 50 which opens through the flat side of the cylinder and ensures lubrication of the joint between the said cylinder and the plate 37. Also a relief port 51 is provided at this end of the cylinder so that the piston 48 may be free in the cylinder. This lubricant chamber is closed by a cylinder head 52 and a piston rod 53 extends from the piston 48 through this head, being provided with an end 54 fitting on a crank pin 55 carried by a crank disc 56. This crank disc is supported on a shaft 57 driven from any suitable source of power, but preferably from the cam shaft of the engine to which the carburetor is connected.

In operation the action of the pump produces a series of vacuum impulses in the chamber to which the conduit 30 leads. This, of course, effects lifting of the fuel from the fuel tank. Now consider the construction shown in Figure l; it will be seen that after a definite amount of fuel has been drawn into the fuel receiving chamber, the float 33 will lift and close the valve 24 thus freeing this chalnber froln the vacuum effeet. New by reason of the horizontal arrangement of the valve 19 the fuel will act under gravity to open this valve and pass down in to the chamber 10. When the float has dropped on to the collar 22 the valve 24 will open and the renewed vacuum in the upper chamber will close the Valve 19.

It is most particularly noted that without the provision of a relief valve between the valve 24 and the suction producing means, this valve 24 would fail to operate and thel device would thus be rendered inoperative for any effective purpose. With the use of a relief valve this diiculty is overcome and moreover, this valve may be adjusted in the usual manner so that precisely the desired degree of even vacuum may be maintained at all times during operation.

There has thus been provided a simple and efficient device of the kind described and for the purpose specified.

It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit there-of. Itis not, therefore, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within tained the maximum of which is substantially constant in said chamber independent of the pressure in the carburetor.

2. The combination with a source of liquid fuel supply, of a carburetor, a fuel receiving chamber communicating therewith, a conduit leading from the source bf supply to the chamber, a suction pump entirely independent of the carburetor but connected to the chamber, and a relief valve interposed between the suction or pump and the chamber, whereby an intermittent vacuum is obtained the maximum of which is substantially constant in said chamber independent of the pressure in the carburetor.

3. The combination with a source of liquid fuel supply, of a carburetor, a fuel receiving chamber communicating therewith, a conduit leading from the source of supply to the chamber, a suction pump entirely independent of the carburetor, a second conduit connecting' the suction pump and the chamber, a valve arranged to close the second conduit when the fuel in the chamber reaches a predetermined height, and a relief valve in the second conduit, whereby an intermittent vacuum is obtained the maximum of which is substantially constant in said chamber independent of the pressure in the earburetor.

4. The combination with a source of liquid fuel supply, of a carburetor, a fuel receiving chamber, a valve controlling communication between the fuel receiving chambeil and the carburetor, a conduit leading from the source of supply to the chamber, a suction pump entirely independent of the carburetor, a second conduit connecting the suction pump and the chamber, a valve arranged to close the second conduit when the fuel in the chamber reaches a predetermined height, and a` relief valve in the second conduit, whereby an intermittent vacuum is obtained the maximum of which is substantially constant in said chamber inde-pendent of the pressure in the carburetor.

5. The combination with a source of liquid fuel supply, of a carburetor, a fuel receiving chamber communicating therewith, a conduit leading from the source of supply to the chamber, a source of suction entirely independent of the carburetor. a second conduit connecting the source of suction to the chamber, and a relief valve connected to said second conduit and controlled by the source of suction, whereby an intern'iittent vacuum is obtained the maximum of which is substantially constant in said chamber inde-- pendent of the pressure in the carbiu'etor.

In testimony whereof I affix my signature.

FLOYD F. FLINT. 

